America does have a "excessive portion size" problem per se, but "appropriate portion" should vary depending on what you are eating. In America, it often doesn'

America does have a "excessive portion size" problem per se, but "appropriate portion" should vary depending on what you are eating. In America, it often doesn't. It's pretty easy to Google 2500+ calorie monstrosities that are served as a dinner in American restaurants. We have pastas with rich sauces (lots of butter, oils, or sugar), dishes with excessive cheese, and large amounts of deep fried ingredients... and many places serve a heck of a lot of this when you go out to eat. Other countries have rich foods too, but my experience is that many cultures with very rich food often go light on the portion size (France comes to mind). Another set of countries have cuisine that normally is not very rich or excessively sweet (like you mention with Japan and the lack of sugary products). In many cases the food is flavored with spice instead of fats and sugars. For these type of foods, I bet you could easily match the portion size of one of those big American restaurant meals, and come nowhere near the calories. Another factor that probably doesn't help here is that America seems more soda oriented than many cultures, and that excessive use of sugar even applies to other drinks all down the chain (my impression is that other cultures use way less sugar on coffee, tea, alcoholic cocktails...). It all adds up.